A Manual Standup Wheelchair Abstract Wheelchairs in the modern form have been around since at least 1760, when John Joseph Merlin invented pushrim propulsion. The Merlin Chair, as it was called, bears a remarkable resemblance to wheelchairs today, despite the intervening 240 years. Wheelchairs capable of erecting a user to the standing position have also been around for a long time, and have numerous physiological and psychological advantages, but to present, have required electric motor drive systems for movement while standing. This results in such wheelchairs being heavy and expensive. A standup wheelchair that is totally manually operated both in the erecting mechanism and the propulsion while standing would offer numerous benefits. The wheelchair presented in this proposal is designed to be lightweight, have a unique and innovative method of propulsion both seated and standing, incorporate drive ratio changing gearing for propulsion, have a very stable erection mechanism, and be aesthetically unobtrusive. PUBLIC HEALTH RELEVANCE: Where applicable, pushrim drive manual wheelchairs are the mobility solution of choice by users for their simplicity and intuitive utility, and are preferred by health care professionals for their health benefit. Thus, improvements of the manual drive wheelchair have occupied many researchers, and been funded by many agencies both private and governmental. Yet with all of this work, standup wheelchairs that provide for mobility while standing always have electric motor drives. To this time, lever drive systems have not been successfully adapted to the standup chair. They are considered too heavy, hard to learn to use, and most importantly aesthetically obtrusive. The use of the lever drive removes the weight penalty of battery sourced electric drive, and necessitates an erection mechanism that places the standing person within the chair wheelbase in order to maximize stability. Responding to the needs of this user population, this standup wheelchair incorporates a innovative lever drive system and a unique standup mechanism. The chair allows manual propulsion by a unique intuitive directional control concept that makes the lever drive available both sitting and standing. It is very light in weight, offers variable ratios to suit changing situations, and is unobtrusive. Additionally, this lever drive system does not interfere with propulsion by both pushrims, which are maintained in the conventional positions. The light weight of this fully mobile manual standup wheelchair opens the possibility of use by those who cannot, or prefer not to purchase an extra wheelchair, but would value the pain relieving, and injury preventive attributes of standing.